Ingredients:

15g/.5oz butter, 2 tablespoons oil, 1 finely chopped medium onion, 450g/1lb cooked lamb burger (minced lamb), 150ml/ .25 pint rich gravy, 2 teaspoons Worcestershir sauce, 1 tablespoon chopped parsley, .25 teaspoon dried mixed herbs, salt and freshly ground black pepper.
Topping: 6 tablespoons double cream, 40g/1.5 oz melted butter, 2 lightly beaten eggs, 900g/2lb boiled and mashed potatoes, 75g/3oz grated Cheddar cheese.

Method:
Greese a deep 1.75 litre/3 pint ovenproof dish with the butter. Heat the oil in a saucepan. Add the onion and sauté for 5 minutes. Stir in the lamb, gravy, Worcestershire sauce, parsley, herbs and seasoning to taste. Place in the dish. Beat the cream, 25g/1oz of the butter and the eggs into the hot mashed potato. Add the cheese, mix to blend and season to taste. Pipe or spoon the mashed potato on top of the meat mixture and brush with the remaining melted butter. Bake in a moderately hot oven (200 c, 400F, Gas Mark 6) for 20-25 minutes until puffed and golden brown.